X represents the FIRST of the three odd integers. So simply solve for X, and you will have found the first odd number. The next number will be 2 MORE than X as described by the (x+2).
\[\large x+(x+2)+(x+4)=537 \quad \rightarrow \quad x+x+2+x+4=537\]\[\large 3x+6=537\]Understand how I combined the x's?